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| author | Radim Krčmář <rkrcmar@redhat.com> | 2017-09-08 14:40:43 +0200 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2017-09-08 14:40:43 +0200 |
| commit | 5f54c8b2d4fad95d1f8ecbe023ebe6038e6d3760 (patch) | |
| tree | daca83ea5f9af1bd158504bd0b5af89c5a99b7fa /arch/x86/mm/mmap.c | |
| parent | Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff) | |
| parent | KVM: PPC: Book3S HV: Protect updates to spapr_tce_tables list (diff) | |
| download | linux-5f54c8b2d4fad95d1f8ecbe023ebe6038e6d3760.tar.xz linux-5f54c8b2d4fad95d1f8ecbe023ebe6038e6d3760.zip | |
Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
This fix was intended for 4.13, but didn't get in because both
maintainers were on vacation.
Paul Mackerras:
"It adds mutual exclusion between list_add_rcu and list_del_rcu calls
on the kvm->arch.spapr_tce_tables list. Without this, userspace could
potentially trigger corruption of the list and cause a host crash or
worse."
Diffstat (limited to 'arch/x86/mm/mmap.c')
| -rw-r--r-- | arch/x86/mm/mmap.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 229d04a83f85..a88cfbfbd078 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -50,8 +50,7 @@ unsigned long tasksize_64bit(void) static unsigned long stack_maxrandom_size(unsigned long task_size) { unsigned long max = 0; - if ((current->flags & PF_RANDOMIZE) && - !(current->personality & ADDR_NO_RANDOMIZE)) { + if (current->flags & PF_RANDOMIZE) { max = (-1UL) & __STACK_RND_MASK(task_size == tasksize_32bit()); max <<= PAGE_SHIFT; } @@ -79,13 +78,13 @@ static int mmap_is_legacy(void) static unsigned long arch_rnd(unsigned int rndbits) { + if (!(current->flags & PF_RANDOMIZE)) + return 0; return (get_random_long() & ((1UL << rndbits) - 1)) << PAGE_SHIFT; } unsigned long arch_mmap_rnd(void) { - if (!(current->flags & PF_RANDOMIZE)) - return 0; return arch_rnd(mmap_is_ia32() ? mmap32_rnd_bits : mmap64_rnd_bits); } |